Chapter 8, Problem 1QQ

To determine

The group of particles having greatest mass among the given options.

Answer to Problem 1QQ

Among the given options, the group of particles that has the greatest mass is (c) four individual protons.

Explanation of Solution

Introduction:

The mass of particles is generally expressed in atomic mass units. One atomic mass unit is equal to $\frac{1}{12}$ the of the mass of Carbon-12 atom.

A helium nuclide has a mass 4.002602 u

The mass of a proton in atomic mass units is 1.007276 u. Therefore, the mass of 4 protons is $4\times 1.007276\text{ u}=4.0291\text{ u}$.

The mass of an electron is 0.00054858 u. The mass of 4 electrons is $\text{4}\times 0.00054858\text{ u}=0.002194\text{ u}$.

Conclusion:

Thus, it can be seen that the mass of 4 protons (4.0291 u) is the greatest among the three groups given. Hence the correct option is (c).